1. Field of the Disclosure
The disclosure is directed to a workpiece carrier system loosely placed on a friction conveyor such as a roller conveyor, a belt conveyor or a plate conveyor. The disclosure is further directed to a friction conveyor that is particularly useful for conveying such workpiece carrier systems.
2. Discussion of the Background Art
Particularly in mass production, conveyor means are used to transport workpieces between individual workplaces where the workpieces are assembled or processed, for example. To do so, the workpieces are placed on workpiece carrier system and the workpiece carrier system is moved together with the workpieces by corresponding conveyor means. Friction conveyors are known for displacing the workpiece carrier system. With friction conveyors, the workpiece carrier system are not rigidly connected with the conveyor means, but may rest on rollers, for example. The displacement of the workpiece carrier system is effected through friction forces occurring between the rollers, belts or plates and friction surfaces of the workpiece carrier system. It is a particular advantage of friction conveyors that they allow for a back-up of the workpiece carrier system. Here, during the back-up process, the corresponding drive means of the friction conveyors slip. Friction conveyors require no intricate and complicated unlatching from a conveyor means, such as a chain. Another advantage of friction conveyors is that curves and especially branches can be realized in a simple manner. Using branching means, such as points, individual workpiece carrier system may be discharged or introduced, for example. Thus, friction conveyors have a great flexibility. Such a friction conveyor is described in DE 40 36 214.
If the workpieces are heavy workpieces, particularly weighing over 100 kg, and/or workpieces of large dimensions, friction conveyors have the drawback that unfavourable friction conditions occur especially in the area of curves and branches. The friction conditions occurring when workpiece carriers back up are disadvantageous as well. Another drawback of friction conveyors for large workpieces is that the conveyor paths have to be made very wide. This increases the costs of such friction conveyors.
It is an object of the disclosure to provide a workpiece carrier system that is particularly suited for receiving heavy and/or large workpieces. Further, it is an object of the disclosure to provide a friction conveyor for large and/or heavy workpieces, suitable in particular for the displacement of corresponding workpiece carrier system.